Service vehicle for a storage system

ABSTRACT

The invention concerns a service vehicle ( 2 ) for movement on a rail system ( 108 ). The service vehicle ( 2 ) comprises a container vehicle handling part ( 8 ) for mechanical interacting with a container handling vehicle ( 300 ) operating on the rail system ( 108 ), an operational part ( 3 ) for controlling operations of the service vehicle ( 2 ) and caterpillar tracks ( 6 ) for allowing movement of the service vehicle ( 2 ) on the rail system ( 108 ) during operation.

TECHNICAL FIELD

The present invention relates to an automated storage and retrievalsystem, a service vehicle for transporting at least one storagecontainer vehicles and a method thereof.

BACKGROUND AND PRIOR ART

FIGS. 1A and 2A disclose a typical prior art automated storage andretrieval system 1 with a framework structure 100. FIGS. 2A and 2Bdisclose a prior art container handling vehicle 101 operating the system1 disclosed in FIGS. 1A and 2A, respectively.

The framework structure 100 comprises a plurality of upright members 102and optionally a plurality of horizontal members 103 supporting theupright members 102. The members 102, 103 may typically be made ofmetal, e.g. extruded aluminum profiles.

The framework structure 100 defines a storage grid 104 comprisingstorage columns 105 arranged in rows, in which storage columns 105storage containers 106, also known as bins, are stacked one on top ofanother to form stacks 107.

Each storage container 106 may typically hold a plurality of productitems (not shown), and the product items within a storage container 106may be identical, or may be of different product types depending on theapplication.

The storage grid 104 guards against horizontal movement of thecontainers 106 in the stacks 107, and guides vertical movement of thecontainers 106, but does normally not otherwise support the storagecontainers 106 when stacked.

The automated storage and retrieval system 1 comprises a rail system 108arranged in a grid pattern across the top of the storage 104 along ahorizontal plane P, on which rail system 108 a plurality of containerhandling vehicles 200,300 (as exemplified in FIGS. 1B and 2B) areoperated to raise storage containers 106 from, and lower storagecontainers 106 into, the storage columns 105, and also to transport thestorage containers 106 above the storage columns 105. The horizontalextension of one of the grid cells 122 constituting the grid pattern isin FIGS. 1A and 2A marked by thick lines.

Each grid cell 122 has a width which is typically within the interval of30 to 150 cm, and a length which is typically within the interval of 50to 200 cm. Each grid opening 115 has a width and a length which istypically 2 to 10 cm less than the width and the length of the grid cell122 due to the horizontal extent of the rails 110,111.

The rail system 108 comprises a first set of parallel rails 110 arrangedto guide movement of the container handling vehicles 200,300 in a firstdirection X across the top of the frame structure 100, and a second setof parallel rails 111 arranged perpendicular to the first set of rails110 to guide movement of the container handling vehicles 200,300 in asecond direction Y which is perpendicular to the first direction X. Inthis way, the rail system 108 defines grid columns above which thecontainer handling vehicles 200,300 can move laterally above the storagecolumns 105, i.e. in a plane which is parallel to the horizontal X-Yplane.

Each prior art container handling vehicle 200,300 comprises a vehiclebody/framework and a wheel arrangement of eight wheels 201,301 where afirst set of four wheels enable the lateral movement of the containerhandling vehicles 200,300 in the X direction and a second set of theremaining four wheels enable the lateral movement in the Y direction.One or both sets of wheels in the wheel arrangement can be lifted andlowered, so that the first set of wheels and/or the second set of wheelscan be engaged with the respective set of rails 110, 111 at any onetime.

Each prior art container handling vehicle 200,300 also comprises alifting device (not shown) for vertical transportation of storagecontainers 106, e.g. raising a storage container 106 from, and loweringa storage container 106 into, a storage column 105. The lifting devicecomprises one or more gripping/engaging devices (not shown) which areadapted to engage a storage container 106, and which gripping/engagingdevices can be lowered from the vehicle 201,301 so that the position ofthe gripping/engaging devices with respect to the vehicle 201,301 can beadjusted in a third direction Z which is orthogonal the first directionX and the second direction Y.

Conventionally, and also for the purpose of this application, Z=1identifies the uppermost layer of the grid 104, i.e. the layerimmediately below the rail system 108, Z=2 the second layer below therail system 108, Z=3 the third layer etc. In the exemplary prior artgrid 104 disclosed in FIGS. 1A and 2A, Z=8 identifies the lowermost,bottom layer of the grid 104. Consequently, as an example, and using theCartesian coordinate system X, Y, Z indicated in FIGS. 1A and 2B, thestorage container identified as 106′ in FIG. 1 can be said to occupygrid location or cell X=10, Y=2, Z=3. The container handling vehicles101 can be said to travel in layer Z=0 and each grid column can beidentified by its X and Y coordinates.

Each container handling vehicle 200 comprises a storage compartment orspace (not shown) for receiving and stowing a storage container 106 whentransporting the storage container 106 across the rail system 108. Thestorage space may comprise a cavity arranged centrally within thevehicle body, e.g. as is described in WO2014/090684A1, the contents ofwhich are incorporated herein by reference.

Alternatively, the container handling vehicles 300 may have a cantileverconstruction, as is described in NO317366, the contents of which arealso incorporated herein by reference.

The container handling vehicles 200 may have a footprint, i.e. an extentin the X and Y directions, which is generally equal to the lateralextent of a grid cell 122, i.e. the extent of a grid cell 122 in the Xand Y directions, e.g. as is described in WO2015/193278A1, the contentsof which are incorporated herein by reference. The term “lateral” usedherein may mean “horizontal”.

Alternatively, the container handling vehicles 101 may have a footprintwhich is larger than the lateral area defined by a grid column, e.g. asis disclosed in WO2014/090684A1.

In a storage grid 104, a majority of the grid columns are storagecolumns 105, i.e. grid columns 105 where storage containers 106 arestored in stacks 107. However, a grid 104 normally has at least one gridcolumn which is used not for storing storage containers 106, but whichcomprises a location where the container handling vehicles 200,300 candrop off and/or pick up storage containers 106 so that they can betransported to an access station (not shown) where the storagecontainers 106 can be accessed from outside of the grid 104 ortransferred out of or into the grid 104. Within the art, such a locationis normally referred to as a “port” and the grid column in which theport is located may be referred to as a “port column” 119,120.

The storage grids 104 in FIGS. 1A and 2A comprise two port columns 119and 120. The first port column 119 may for example be a dedicateddrop-off port column where the container handling vehicles 200,300 candrop off storage containers 106 to be transported to an access or atransfer station, and the second port column 120 may be a dedicatedpick-up port column where the container handling vehicles 200,300 canpick up storage containers 106 that have been transported to the storagegrid 104 from an access or a transfer station.

The access station may typically be a picking or a stocking stationwhere product items are removed from or positioned into the storagecontainers 106. In a picking or a stocking station, the storagecontainers 106 are normally never removed from the automated storage andretrieval system 1, but are returned into the storage grid 104 onceaccessed. Alternative to ports as part of the storage grids 104, it maybe envisaged ports that transfer storage containers out of or into thestorage grid 104, e.g. for transferring storage containers 106 toanother storage facility (e.g. to another storage grid), directly to atransport vehicle (e.g. a train or a lorry), or to a productionfacility.

For monitoring and controlling the automated storage and retrievalsystem 1 (e.g. monitoring and controlling the location of respectivestorage containers 106 within the storage grid 104; the content of eachstorage container 106; and the movement of the container handlingvehicles 200,300 so that a desired storage container 106 can bedelivered to the desired location at the desired time without thecontainer handling vehicles 200,300 colliding with each other), theautomated storage and retrieval system 1 comprises a control system (notshown) which typically is computerized and which typically comprises adatabase for keeping rail of the storage containers 106.

A problem associated with known automated storage and retrieval systems1 is that it is challenging for personnel to access the rail system 108for carrying out inspection, or to carry out maintenance of or to removemalfunctioning container handling vehicles 200,300.

WO2015/140216A1 discloses a service vehicle for cleaning the grid andfor inspection of the grid. The service vehicle is arranged with areleasable latching mechanism for docking with a malfunctioningcontainer handling vehicle. After connecting with the vehicle, theservice vehicle brings the vehicle to a designated location on the gridfor inspection and maintenance by pulling or pushing. This publicationalso suggests an overhead carrying arrangement for removing amalfunctioning vehicle from the grid. In this arrangement either abridge-shaped robotic vehicle or two parallelly arranged roboticvehicles connected with a cross beam is/are arranged with a lift forelevating the load handling device from the grid. The malfunctioningvehicle is carried in this elevated position to the designated location.In addition, the publication suggests that the service vehicle may bearranged with a seat for carrying a user to inspect and carry outmaintenance. This personnel carrying version of the service vehicle maybe manually operated by the user, or alternatively remotely controlledby the control system.

However, the known service vehicle is restricted to follow theunderlying grid system, i.e. in the X and Y directions only. The servicevehicle thus moves on the grid in the same way as that of load handlingdevice, thus occupying a large amount of space during the serviceprocedure due to the zigzag movement pattern both ways. The particularmovement pattern also increases the time spent on the grid. In the caseof automated storage and retrieval systems having a high density ofcontainer handling vehicles, such use of space and time may reducesignificantly the overall efficiency. Further, the push or pull methodmay prove cumbersome and thereby add additional operational time of theservice vehicle on the rail system.

In view of the above, it is desirable to provide a service vehicle, anautomated storage and retrieval system using such a service vehicle, anda method thereof, that solve or at least mitigate one or more of theaforementioned problem related to use of prior art storage and retrievalsystems.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independentclaims, while the dependent claims describe other characteristics of theinvention.

In a first aspect the invention concerns a service vehicle for movementon a rail system. The rail system may comprise a first set of parallelrails arranged in a horizontal plane P and extending in a firstdirection X, and a second set of parallel rails arranged in thehorizontal plane P and extending in a second direction Y which isorthogonal to the first direction X, which first and second sets ofrails form a grid pattern in the horizontal plane P comprising aplurality of adjacent grid cells.

The service vehicle comprises a vehicle body or framework and propulsionmeans or propulsion mechanism, hereinafter called roller, for allowingmovement of the service vehicle over the top of the rail system duringoperation. The vehicle body/framework contains or support vehiclehandling components/a container vehicle handling part for mechanicalinteracting with a container handling vehicle operating on the railsystem and operational components/an operational part for controllingoperations of the service vehicle other than the direct handling of theat least one container handling vehicle. The container vehicle handlingpart and the operational part may be separated fully or partly in space.

The roller may be any propulsion means or propulsion mechanismsconfigured to run over the top of the rail system, for examplecaterpillar tracks.

Hereinafter the term ‘over the top of the rail system’ signifies thatthe propulsion means rest on the rail system, but do not engage with therails themselves. Hence, the service vehicle is not restricted tomovement only in the direction of the rails but can move in anydirection over the top of the rail system.

The roller may advantageously have an overall length L exceeding thedistance across two grid cells in the first direction X and/or acrosstwo grid cells in the second direction Y when the service vehicle ismoving on top of the rail system. In a more preferred configuration, theroller has an overall length L exceeding the distance across three gridcells in the first and/or the second direction X, Y, for example across3.5 grid cells. These minimum lengths of the roller ensure safe movementof the service vehicle on the rail system. In addition, the minimumlengths ensure that the roller spreads the weight of the service vehicleacross the top of several rails at any one time.

The overall length L may for example be 350 cm or more.

The term “overall length L” signifies herein the length from oneextremity of the roller along its longitudinal direction to the oppositeextremity of the roller along its longitudinal direction.

In order to further increase overall stability during operation on therail system, and in particular directional stability, the roller mayfurther have an overall width W that exceeds the width of adjacent railswhen the service vehicle is moving on the rail system, i.e. exceed thewidth of one grid cell.

The term “overall width W” signifies herein the width from one extremityof the roller perpendicular to its longitudinal direction to theopposite extremity of the roller perpendicular to its longitudinaldirection, including any gap G therebetween.

The roller may comprise a longitudinal extending endless belt of thelength L and a belt motor driving the endless belt. The belt may be madeof a flexible or resilient material such a material comprising rubber.Alternatively, or in addition, the coupling of the roller to the vehiclebody may comprise a spring arrangement. The flexibility of the rollerensures a stable operation with low risk of damaging the underlyingrails.

The roller may comprise at least one roller wheel, preferably at leasttwo roller wheels, contacting the first endless belt. Further, the beltmotor may drive the endless belt via the at least one wheel or aseparate wheel or a combination of both.

The at least one roller wheel may contact an inner surface of theendless belt, for example by a configuration where the endless belt issurrounding the at least one roller wheel. The rotational axis of the atleast one roller wheels may be parallel to a rotational axis of theendless belt. The term ‘inner surface of the endless belt’ signifiesherein the surface of the belt facing towards the volume of the beltconfined by the belt's width W and length L.

The at least one roller wheel may act as a propulsion unit for the beltsor as a tightening means for the belt or a combination thereof.

In case of at least two roller wheels it is advantageous to arrangeroller wheels at each longitudinal ends of the roller.

The roller may further comprise a first caterpillar track comprising alongitudinal extending endless belt and a second caterpillar trackcomprising a longitudinally extending endless belt directed parallel tothe first caterpillar track, for example attached to opposite side wallsof a vehicle body of the service vehicle. The first caterpillar trackand the second caterpillar track may be spaced apart by a gap G measuredalong the direction of the rotational axis of the endless belts. Thewidth of gap G is in this embodiment preferably at least the width of agrid cell of the rail system in either the first direction X or thesecond direction Y.

The first and/or second caterpillar tracks is/are preferably arrangedsuch that endless belt(s) is/are at least partly extending beyond avehicle body containing and/or supporting the container vehicle handlingpart and the operational part in the direction of the rotational axis toi.a. create physical barriers protecting the operator against collisionswith objects located on the rail system.

In order to ensure sufficient stiffness of the belts, and thereby ensurethat the service vehicle is moving satisfactory over the top of the railsystem, each belt preferably comprise one or more struttings. A furtherdesirable increase in overall stiffness of the roller may be achieved byadding stabilization wheels contacting the belt or belts, for example ontop of the belt(s) relative to the rail system.

Further, the roller may advantageously be connected symmetrically in thehorizontal plane (P) to the vehicle body. For example, the first andsecond caterpillar tracks may be arranged at the exterior side walls ofthe service vehicle's vehicle body symmetrically around a center axis ofthe vehicle body running perpendicular to the rollers' rotational axis.

The container vehicle handling part may include a transfer deviceconfigured to transfer at least one container handling vehicle betweenan operating position on the rail system, that is, a lower positionwhere the container handling vehicle is movable on the rail system, anda transport position within the vehicle body during operation, i.e. anupper position where the container handling vehicle is lifted above therail system. The container vehicle handling part may also include atransfer motor configured to power the transfer device, thereby allowingsaid transfer of the container handling vehicle.

If the roller comprises two caterpillar tracks, the transfer device maybe arranged at least partly between the first and second caterpillartracks, for example fully within the container vehicle handling part andapproximately centered within the gap G relative to the belts rotationalaxis.

In a first exemplary configuration of the service vehicle, the transferdevice is configured to support the container handling vehicle frombelow, for example by applying a base plate onto which the containerhandling vehicle may be supported.

For this first exemplary configuration the transfer device mayconfigured move between an upper and a lower position relative to thehorizontal plane P and may further be configured to allow the containerhandling vehicle to move from its operating position on the rail systemto a transport position on the base plate when the transfer device is inits lower position.

The operational part may comprise a propulsion means motor or a rollerdevice motor, hereinafter called a roller motor, allowing movement ofthe service vehicle along the horizontal plane P. The operational partmay further comprise an onboard operating system allowing an onboardoperator to control and regulate both the direction and the speed of theservice vehicle relative to the underlying rail system. The change indirection may cover a 360° rotation of the service vehicle.Alternatively, said operating system may be remotely located, henceregulating the direction and the speed of the service vehicle by remotecontrol.

A configuration of the service vehicle allowing vertical displacement ofthe operational part or the container vehicle handling part or both mayalso be envisaged. The control and regulation of the speed also includesstart and full halt.

The service vehicle may further comprise a registration unit such as animage capturing unit being configured to allow visual inspection of thesurroundings of the service vehicle. The image capturing unit may forexample comprise a forward camera and a rearward camera, either fixed orrotatable relative to the horizontal plane P.

The service vehicle is arranged for transporting at least one of the atleast one container handling vehicle in the horizontal plane P andpreferably also for transporting one or more people. Alternatively, theservice vehicle may be remotely controlled.

The service vehicle may further comprise a transmitter and/or receiverfor establishing signal communication with a remote control system.

The transfer device may comprise an attachment device for releasableattachment to the at least one container handling vehicle, a verticallinear actuator attached at one end at least indirectly to the vehiclebody, for example via a pivot support, and the other end at leastindirectly to the attachment device, wherein the vertical linearactuator is configured to displace the attachment device relative to thevehicle body in a vertical direction.

The transfer device may further comprise a horizontal linear actuatorfixed to the vehicle body and which is configured to displace theattachment device relative to the vehicle body in a horizontaldirection.

In a second aspect, the invention concerns an automated storage andretrieval system.

The system includes a rail system comprising a first set of parallelrails arranged in a horizontal plane P and extending in a firstdirection X, and a second set of parallel rails arranged in thehorizontal plane P and extending in a second direction Y which isorthogonal to the first direction X, which first and second sets ofrails form a grid pattern in the horizontal plane P comprising aplurality of adjacent grid cells and a service vehicle as describedabove.

The system may further comprise at least one container handling vehiclebeing configured to move on the rail system, wherein the at least onecontainer handling vehicle comprises a wheel arrangement beingconfigured to guide the at least one storage container vehicle along therail system in at least one of the first direction X and the seconddirection Y.

The service vehicle may comprise a vehicle body/framework containing orsupporting a container vehicle handling part for mechanical interactionwith at least one of the at least one container handling vehicleoperating on the rail system and an operational part for controllingoperations of the service vehicle and a roller connected to the vehiclebody allowing movement of the service vehicle on the rail system duringoperation. The roller has preferably a length L which exceeds thedistance across two grid cells in the first direction X or the seconddirection Y when the service vehicle is moving on the rail system, morepreferably a length L which exceeds the distance across three gridcells, for example between three and four grid cells.

The service vehicle may be in accordance with any features describedabove.

In a third aspect, the invention concerns a method for operating aservice vehicle comprising a vehicle body. The vehicle bodycontains/supports a container vehicle handling part and an operationalpart. The service vehicle is configured to move over the top of a railsystem comprising a first set of parallel rails arranged in thehorizontal plane P and extending in a first direction X, and a secondset of parallel rails arranged in the horizontal plane P and extendingin a second direction Y which is orthogonal to the first direction X,which first and second sets of rails form a grid pattern in thehorizontal plane P comprising a plurality of adjacent grid cells, eachgrid cell comprising a grid opening defined by a pair of neighboringrails of the first set of rails and a pair of neighboring rails of thesecond set of rails.

The method comprises the following steps:

-   -   guiding the service vehicle to a first position on the rail        system adjacent to at least one storage container vehicle by use        of the operational part,    -   controlling a transfer device constituting part of the container        vehicle handling part to transfer the at least one container        handling vehicle between an operating position on the rail        system and a transport position above the rail system, for        example within the vehicle body, and    -   guiding the service vehicle to a predetermined second position        on the rail system.

The service vehicle used in the method may be in accordance with theservice vehicle disclosed above.

In an alternative configuration the vehicle body of the service vehiclecomprises a fence. The fence defines a loading area of the servicevehicle configured for containing at least one storage containervehicles. The fence may further comprise an access ramp pivotallyconnected to the vehicle body for pivoting the access ramp between aninclined, lower position relative to the underlying rail system allowingthe one or more storage container vehicle to be transported between therail system and the loading area via the access ramp and a closing,upper position for closing off the loading area.

The loading area of the fence may also, or alternatively, be configuredto accommodate one or more operators. In this configuration fence actsas a protective chamber for the personnel.

A protective barrier such as the protective chamber or rollers connectedat the outer surface of the vehicle body is a clear advantage comparedwith the personnel carrying service vehicle disclosed in WO2015/140216A1where the open operational part of the service vehicle offers little orno protection for the operator, for example in case of a collisionbetween the service vehicle and obstacles on the rail system such as thecontainer handling vehicles.

In yet an alternative configuration the vehicle body is movably arrangedrelative to the first and second belted driving wheel assembly between

-   -   a transport position, wherein a transfer device is at least        partly within the horizontal extent of the first and/or second        endless belt(s) perpendicular to its or their rotational axis        for carrying the container handling vehicle during transport and    -   a operational position, wherein the transfer device is        positioned outside the horizontal extend of the first and/or        second endless belt(s) perpendicular to its or their rotational        axis, such that lifting and lowering of the container handling        vehicle is possible.

BRIEF DESCRIPTION OF THE DRAWINGS

Following drawings are appended to facilitate the understanding of theinvention.

FIGS. 1 and 2 are perspectives view of a prior art automated storage andretrieval system, where FIG. 1 A and FIG. 2 A shows the complete systemand FIG. 1 B and FIG. 2 B shows examples of system operable prior artcontainer handling vehicles.

FIG. 3 is a perspective view of a service vehicle according to a firstembodiment of the invention, operating on a rail system of an automatedstorage and retrieval system.

FIGS. 4 A-C are perspective views of the service vehicle according toFIG. 3 without a container handling vehicle and including an operator,where FIG. 4 A shows a front part of the service vehicle, FIG. 4 B showsa rear part of the service vehicle and FIG. 4 C shows the servicevehicle from the side.

FIGS. 5 A and B are perspective side views of the service vehicleaccording to FIGS. 3 and 4, where FIG. 5 A and FIG. 5 B show a handlingdevice of the service vehicle in an interacting position and a transportposition, respectively.

FIGS. 6 A and B are perspective views of a service vehicle according toa second embodiment of the invention, operating on a rail system of anautomated storage and retrieval system, where FIG. 6 A and FIG. 6 Bshows the service vehicle with and without an operator, respectively.

FIGS. 7 A-D are perspective views of the service vehicle according toFIG. 6, where FIG. 7 A shows a handling mechanism of the service vehiclein a transport position on the rail system, located adjacent to acontainer handling vehicle to be serviced, FIGS. 7 B and C show thehandling mechanism of the service vehicle in an interacting position,before and after successful interaction with the container handlingvehicle, respectively, and FIG. 7 D shows the service vehicle supportingthe container handling vehicle by use of the handling mechanism.

FIGS. 8 A and B are perspective side views from two different directionsof the service vehicle according to FIGS. 6 and 7 showing the servicevehicle supporting a container handling vehicle to be serviced.

FIG. 9 is a perspective side view of the service vehicle according toFIGS. 6-8, showing the operator in a position within the surface vehiclewhere he can access objects situated on or below the rail system.

FIG. 10 is a perspective side view of a container handling vehiclesupporting service vehicle according to a third embodiment of theinvention, operating on a rail system of an automated storage andretrieval system.

FIGS. 11 A-C are perspective side views of the service vehicle of FIG.10, where FIG. 11 A shows the service vehicle approaching a containerhandling vehicle to be serviced and with a handling mechanism of theservice vehicle set in a transport position, FIG. 11 B shows the servicevehicle adjacent to the container handling vehicle in a position withinreach of the handling mechanism and FIG. 11 C shows the service vehiclesupporting the container handling vehicle by use of the handlingmechanism.

FIG. 12 is a perspective side view of a service vehicle according to afourth embodiment of the invention operating on a rail system of anautomated storage and retrieval system.

FIGS. 13 A-D are perspective side views of the service vehicle of FIG.12, where FIG. 13 A shows the service vehicle in a transport positionnear the location on the rail system where the container handlingvehicle is to be placed, FIG. 13 B shows the service vehicle in aninteracting position enabling the container handling vehicle to be movedfrom the service vehicle to the rail system and FIGS. 13 C and D showthe service vehicle in the interacting position with the containerhandling vehicle in an intermediate position on the service vehicle andin an operational position on the rail system, respectively.

FIG. 14 is a perspective side view of the service vehicle of FIGS. 12and 13, showing the operator in a position within the surface vehiclewhere he can access objects situated on or below the rail system.

FIGS. 15 A and B are perspective side views of a service vehicleaccording to a fifth embodiment of the invention with a handlingmechanism in a transport position, where FIG. 15 A shows the servicevehicle without a container handling vehicle and FIG. 15 B shows theservice vehicle on a rail system of an automated storage and retrievalsystem supporting a container handling vehicle by use of the handlingmechanism.

FIGS. 16 A-C are perspective side views of a service vehicle accordingto a sixth embodiment of the invention being configured to be operatedremotely.

FIGS. 17 A-C are perspective side views of the service vehicle of FIG.16, where FIG. 17 A shows the service vehicle approaching a containerhandling vehicle to be serviced, FIG. 17 B shows the service vehiclepartly surrounding the container handling vehicle and FIG. 17 C showsthe service vehicle gripping the container handling vehicle by use ofits handling mechanism.

FIGS. 18 A and B are perspective side views of the service vehicle ofFIGS. 16 and 17, where FIG. 18 A and FIG. 18 B show the service vehiclein an operating position where the container handling vehicle iscontacting the rail system and a transport position where the containerhandling vehicle is raised above the rail system, respectively.

In the drawings, the same reference numerals have been used to indicatelike parts, elements or features unless otherwise explicitly stated orimplicitly understood from the context.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments of the invention will be discussed in moredetail with reference to the appended drawings. It should be understood,however, that the drawings are not intended to limit the invention tothe subject-matter depicted in the drawings.

With reference to FIGS. 1 and 2 the storage grid 104 of each storagestructure 1 constitutes a framework 100 of in total 1144 grid cells,where the width and length of the framework corresponds to the width andlength of 143 grid columns. The top layer of the framework 100 is a railsystem 108 onto which a plurality of container handling vehicles 200,300are operated.

The framework 100 of the inventive automated storage and retrievalsystem 1 is constructed in accordance with the prior art framework 100described above, i.e. a plurality of upright members 102 and a pluralityof horizontal members 103 which are supported by the upright members103, and further that the horizontal members 103 includes the railsystem 108 of parallel rails 110,111 in the X direction and the Ydirection, respectively, arranged across the top of storage columns 105.The horizontal area of a single grid cell, i.e. along the X and Ydirections, may be defined by the distance between adjacent rails 110and 111, respectively (see also FIGS. 3 and 4). In FIGS. 1 and 2, such agrid cell 122 is marked on the rail system 108 by thick lines.

The rail system 108 allows the container handling vehicles 200,300 tomove horizontally between different grid locations, where each gridlocation is associated with a grid cell 122.

In FIGS. 1 and 2 the storage grid 104 is shown with a height of eightcells. It is understood, however, that the storage grid 104 can inprinciple be of any size. In particular it is understood that storagegrid 104 can be considerably wider and/or longer than disclosed in FIGS.1 and 2. For example, the grid 104 may have a horizontal extension ofmore than 700×700 grid cells 122. Also, the grid 104 can be considerablydeeper than disclosed in FIGS. 1 and 2. For example, the storage grid104 may be more than twelve grid cells deep.

The storage container vehicles 200,300 may be of any type known in theart, e.g. any one of the automated container handling vehicles disclosedin WO2014/090684 A1, in NO317366 or in WO2015/193278A1.

FIGS. 3-5 show a first embodiment of a service vehicle 2 arranged on therail system 108. The service vehicle 3 comprises a vehicle body 3 andtwo rollers in form of caterpillar tracks 6,7, each comprising anendless belt 6 d with length L and arranged at least partly below thevehicle body 3. Each of the rollers 6,7 is driven by aid of a belt motorand a belt wheel 6 a,6 b arranged within the belts 6 d at both beltends, i.e. at the rollers' front and rear. In one exemplaryconfiguration a common belt motor is used for both belts 6 d.

The first and second rollers 6,7 are arranged symmetrically around avertical centerplane of the service vehicle 2 in its direction ofmovement and are protruding at least partly from the horizontalextremity of the vehicle body 3. The service vehicle 2 may be dividedinto two functional parts, a container vehicle handling part 4 includingthe components responsible for any mechanical interaction with thecontainer handling vehicle 200,300 to be serviced and an operationalpart 5 including any components responsible for the operation of theservice vehicle 2. In this particular embodiment the two parts areseparated in space relative to the horizontal extent of the servicevehicle 2.

Each of the first and second rollers 6,7 comprises in the example shownin FIG. 3-5 a looped chain 6 d and two toothed belt wheels 6 a,6 barranged inside the chain 6 d at each of the rollers 6,7 longitudinalends. The first toothed belt wheel 6 a are arranged at the terminal end(front and rear) of the chains 6 d and has a diameter sufficiently largeto mesh with both the lower and upper parts of the chain 6 d. The secondtoothed belt wheel 6 b has in the example a smaller diameter than thefirst toothed belt wheel 6 a and is arranged to mesh with the lowerparts of the chains 6 d at a location further towards the longitudinalcenter of the rollers 6,7.

Note that the terms “upper” and “lower” are measured relative to theunderlying rail system 108.

The looped chains 6 d constituting the two rollers 6,7, i.e. one chain 6d for each roller 6,7, are preferably made of a resilient materialcapable of not inflicting damages when moving in contact with topsurfaces of the rails 110, 111. For example, each chain 6 d may be atleast partly made of, or covered by, an elastomer such aspolyoxymethylene (POM). Alternatively, or in addition, the top surfacesmay be covered by the same or similar materials.

One or more of the toothed wheels 6 a,6 b and/or one or both of thebelts 6 d, are connected to a driving mechanism comprising a drivingmotor (not shown). For example, one or both of the first toothed beltwheel(s) 6 a of one or both of the belts 6 d may function as a drivewheel which engages and drives its respective roller 6,7. Further, asecond driving motor may be connected to one ore both of the secondtoothed belt wheels 6 b for one or both of the rollers 6,7.

By the arrangement of the first and second rollers 6,7 the servicevehicle 2 is arranged to move horizontally in any direction on the railsystem 108 by a control system 12 located onboard the service vehicle 2or remote from the service vehicle 2 (see also FIGS. 16-18). If thecontrol system 12 is onboard the service vehicle 2, any movement patternand speed settings may be conducted by any operator 50 located insidethe service vehicle 2 by the operation of one or both of the first andsecond rollers 6,7 via its/their motor(s).

In the first embodiment the container vehicle handling part 4 comprisesa transfer device 8 which again includes one or more transfer beams 8 bextending from the operational part 5, a transfer motor 8 c connected tothe transfer beams 8 b and an attachment device 8 d operationallyconnected to the transfer motor 8 c. In the particular embodiment shownin FIGS. 3-5 the attachment device 8 d comprises a lifting hook attachedto a winch line spooled onto a rotatable drum 8 e. However, a skilledperson will understand that any mechanism capable of raising andlowering a container handling vehicle 200,300 relative to the underlyingrail system 108 may be applied.

Further, the operational part 5 comprises an operating system 12 with acontrol stick to regulate the direction of the service vehicle 2relative to the rail system 108 and a speed regulator to regulate to thespeed of the service vehicle 2 relative to the rail system 108. Theoperational part 5 further comprise an operator chair 13 and handles 14on both sides of the vehicle body 3 for facilitating the exit andentrance of the operator 50 out of and into the operator chair 13,respectively. The handles 14 may also be used for other purposes such asattachment points during lifting or lowering procedures of the servicevehicle 2 on to the rail system 108.

As is apparent in FIGS. 3-5, the length L of both rollers or caterpillartracks 6,7 extends over several grid cells 122 to ensure stableoperations on the rail system 108 in all horizontal directions.

The procedure for lifting up a container handling vehicle 200,300according to the first embodiment is best seen in FIG. 5. The operator50 maneuvers the service vehicle 2 to a position where a containerhandling vehicle 300 to be serviced is adjacent to the part of theservice vehicle 2 closest to the transfer device 8. If needed, theoperator 50 may fine adjust the horizontal position of the servicevehicle 2 in order to ensure a horizontal position of the transferdevice 8 ready for attachment to, and lifting of, the container handlingvehicle 300. In the particular configuration shown in FIG. 5, thevehicle body 3 may be horizontally displaced relative to the rollers 6,7as illustrated by the thick arrows, for example by use of a dedicateddisplacement motor and internal rail arrangement (not shown). When thecontainer handling vehicle 300 has been raised to an elevated positionabove the rollers 6,7, the operator 50 may displace the vehicle body 3relative to the rollers 6,7 to a transport position where the containerhandling vehicle 300 is located at least partly within the horizontalextent of the rollers 6,7, to ensure a high stability during horizontalmovements of the service vehicle 2 on the rail system 108.

FIGS. 6-9 show a second embodiment of the inventive service vehicle 2.In this embodiment the transfer device 8 of the service vehicle 2comprises a base plate 8 a of width G being configured to support one ormore container handling vehicles 200,300. The width G should thus beadapted to the overall width of the container handling vehicles 200,300and the number of container handling vehicles 200,300 to be serviced.For example, in order for the service vehicle 2 to allow transportationof at least one container handling vehicle 200,300, the width G shouldbe equal or larger than the corresponding width of the containerhandling vehicle 200,300, thereby allowing entrance onto the base plate8 a.

The procedure for picking up a container handling device 200,300 by theservice vehicle 2 according to the second embodiment may proceed in thefollowing way:

-   -   (FIG. 6 A) An operator 50 operating the service vehicle 2 guides        the service vehicle 2 to a position adjacent to the one or more        container handling vehicles 200,300 to be transported.    -   (FIGS. 7 A and B) When the service vehicle 2 is in position, the        base plate 8 a of the handling device 8 is lowered from a        transport position in which the base plate 8 a is elevated        relative to the underlying rail system 108 to an interacting        position in which the base plate 8 a is contacting, or near        contacting the underlying rail system 108. As is apparent from        the framed detailed drawing in the upper right part of FIGS. 7 A        and B, one edge of the base plate 8 a is adjacent to (FIG. 7 A)        or contacting (FIG. 7 B) the wheel arrangement 201,301 of a        container handling vehicle 200,300.    -   (FIG. 7 C) When the base plate 8 a is in the interacting        position, the one or more container handling vehicles 200,300        are moved onto the base plate 8 a, for example by remote        operation, such that none of the wheels in the wheel arrangement        are in contact with the rail system 108. Alternatively, the        container handling vehicle(s) 200,300 may be kept still and the        service vehicle 2 is moved so that the base plate 8 a is forced        under the container handling vehicle(s) 200,300.    -   (FIG. 7 D) When the one or more container handling vehicles        200,300 are fully in place onto the base plate 8 a, the operator        50 operates the transfer device 8 of the container vehicle        handling part 4 such that the base plate 8 a is lifted from the        interacting position to the transport position.    -   (FIGS. 8 A and B) The service vehicle 2 is moved to its        predetermined position on the rail system 108, or out of the        rail system 108, with the one or more container handling        vehicles 200,300.

The unloading process, i.e. the transport of the one or more containerhandling vehicles 200,300 by the service vehicle 2 to a predeterminedposition onto the rail system 108 for regular operation, proceeds equalor similar to the above described loading process, but in reversesequence.

With particular reference to FIG. 8 A, the length of therollers/caterpillar tracks 6,7 are in this example seen to extend acrossfour grid cells 122.

A grid cell 122 framing a grid opening 115 is marked in FIGS. 6 A and 8B with thick lines.

As for the first embodiment, the rollers 6,7 are driven by aid of a beltmotor and belt wheels 6 a,6 b arranged within the endless belts 6 d atboth belt ends.

FIG. 9 shows that the operator 50 operating the service vehicle 2 of thesecond embodiment may gain access to the rail system 108, and therebyany components on the rail system 108, by using the base plate 8 a assupport.

A third embodiment of the inventive service vehicle 2 is shown in FIGS.10 and 11.

Similar to the first embodiment described above, the transfer device 8comprises a winch arrangement having a support 8 a supporting thecontainer handling vehicle 200,300 from above, a lifting mechanism 8 cin form of a rotatable handle and a transfer drum 8 e connected to thelifting mechanism 8 c. As for the first and second embodiments thecaterpillar tracks/rollers 6,7 have a length L extending across aboutfour grid cells 122 and spaced apart with a width G (see FIG. 11C). Theminimum width of G should be equal to, or larger than, the overall widthof the container handling vehicle(s) 200,300 to be serviced. Further,the looped chains 6 d of the rollers 6,7 are driven by belt wheels 6 a,6b arranged at both longitudinal lengths of the rollers 6,7.

The procedure for picking up a container handling device 200,300 by theservice vehicle 2 according to the third embodiment may proceed in thefollowing way:

-   -   (FIG. 11 A) An operator 50 situated into the service vehicle 2        guides the service vehicle 2 to a position adjacent to the one        or more container handling vehicles 200,300 to be transported.    -   (FIG. 11 B) The position of the service vehicle 2 is fine        adjusted so that the transfer device 8 is in an interacting        position, i.e. directly above, or nearly directly above, the        corresponding attachment mechanism of the one or more container        handling vehicles 200,300 (not shown). This interacting position        may for example be obtained by moving the service vehicle 2 such        that the one or more container handling vehicles 200,300 are        located between the rollers 6,7.    -   (FIG. 11 C) When the transfer device 8 is in the interacting        position, the operator 50 operates, either manually or by the        control system 12 or a combination thereof, the lifting        mechanism 8 c. In FIG. 11 C the lifting mechanism 8 c is a crack        handle coupled to a winch/drum 8 e. By rotating the crank handle        8 c, the attachment device 8 d in form of a hook connected to a        transfer line is lowered and attached to a corresponding        receiving device (not shown) on the one or more container        handling vehicles 200,300.    -   (FIG. 11 C) When the one or more container handling vehicles        200,300 are safely attached to the attachment device 8 c, the        operator operates the lifting mechanism 8 c such that the one or        more container handling vehicles 200,300 are lifted from the        interacting position to the transport position clear from the        rail system 108.    -   (FIG. 10) The service vehicle 2 is moved to its predetermined        position on the rail system 108, or out of the rail system 108,        with the one or more container handling vehicles 200,300.

The unloading process, i.e. the transport of the one or more containerhandling vehicles 200,300 by the service vehicle 2 to a predeterminedposition onto the rail system 108 for regular operation, proceeds equalor similar to the above described loading process, but in reversesequence.

With particular reference to FIG. 10, the length of the rollers 6,7 arealso in this example seen to extend across four grid cells 122.

FIGS. 12-14 show a fourth embodiment of a service vehicle 2 arranged onthe rail system 108. The vehicle body 3 comprises a security fence 33which defines an enclosed area, for example a protective chamber foraccommodating an operator/personnel 50. The protective chamber is in theexample shown in FIGS. 12-14 arranged with seating 13 for the operator50.

The security fence 33 may be made of wall panels arranged on top of ahorizontal base of the vehicle body 3. Further, at least one of the wallpanels may be made of transparent panels.

The transfer device 8 may in this embodiment be a hatch or any otherpivotable device onto which one or more container handling vehicles200,300 may be driven.

The procedure for transferring one or more container handling devices200,300 from the service vehicle 2 to a location on the rail system 108according to the fourth embodiment may proceed in the following way:

-   -   (FIGS. 12 and 13 A) The service vehicle 2 with the operator 50        moves to a position adjacent to one or more storage grid cells        122 on which the container handling vehicle(s) 200,300 to be        serviced is/are located.    -   (FIG. 13 B) When in position, the hatch 8 is opened, either by        the operator 50 (manually and/or by an onboard control system),        by a remote control system or a combination thereof. In fully        opened position the end of the hatch 8 distant from the service        vehicle 2 contacts the underlying rail system 108 at or near one        rail 110,111 framing the targeted grid cell 122.    -   (FIG. 13 C) The one or more container handling vehicles 200,300        are guided onto the rail system 108 via the opened hatch 8        either by the operator 50 (manually and/or by an onboard control        system), by a remote control system or a combination thereof.    -   (FIG. 13 D) The one or more container handling vehicles 200,300        are fine positioned either by the operator 50 (manually and/or        by an onboard control system), by a remote control system or a        combination thereof.

As depicted in FIG. 14, the operator 50 may in one exemplaryconfiguration open an inspection door 34 at the side of the servicevehicle 2, for example opposite the side with the hatch 8. Such aconfiguration may be useful to allow further manual inspection of thestorage system 1.

A fifth embodiment of the service vehicle 2 is illustrated in FIG. 15.The embodiment is similar to the third embodiment (FIGS. 10 and 11) withthe exception of the configuration and operation of the transfer device8.

Instead of a winched crane system 8 c,8 d,8 e depicted in the thirdembodiment, the one or more container handling vehicles 200,300 arelifted by one or more lifting hooks 8 d arranged onto the vehicle body 3within the container vehicle handling part 4. As for the above disclosedembodiments, the rollers 6,7 are spaced apart by a width G.

The term lifting hook 8 d should be interpreted to include any grippingmechanism able to grip a container handling vehicle 200,300.

In this fifth embodiment the lifting hook 8 d is coupled to a liftingarrangement 8 f,8 g enabling vertical movement of the lifting hook 8 d.The lifting arrangement may for example comprise one or more verticallinear actuators 8 f driving a frame 8 g onto which the lifting hook 8 dis mounted. The term ‘vertical linear actuator’ is herein defined as anylinear actuator able to move in a direction having a significantnon-zero vertical component. In a preferred example however, thevertical linear actuator is configured to perform a vertical movementwith zero, or essentially zero, horizontal displacement.

The design of the lifting hook 8 d (or alternative gripping mechanism)should be such that interaction with any exterior design of the vehiclebody of the relevant container handling vehicle(s) 200,300 is allowed.For example, the vehicle body of each container handling vehicle 200,300may comprise one or more receptacles 302 such as recesses/openings/ringsinto which the lifting hook(s) 8 d may be inserted.

The operation of the lifting hook(s) 8 d may be controlled by theoperator 50 (manually and/or by an onboard control system 12), by aremote control system or a combination thereof.

Further, the service vehicle 2 may be equipped by a registration unit 9configured to aid an operator 50 to maneuver the service vehicle 2safely to the final positions on the rail system 108. The registrationunit 9 may for example be an image capturing unit 9 comprising a forwardcamera 9 a and a rearward camera 9 b as illustrated in FIG. 15 and/orone or more rotatable cameras. The image capturing unit 9 may be anyoptical instrument for recording or capturing images. The images orfilms may be stored locally, transmitted to remote location, or acombination thereof.

The image capturing unit 9 may be controlled and visualized by anoperator 50 onboard the service vehicle 2, remotely or a combinationthereof.

Further, the first to fifth embodiments of the service vehicle 2 havepreferably an emergency stop button 12 a as depicted in FIG. 15,constituting part of the onboard control system 12.

FIGS. 16-18 show a sixth embodiment of the service vehicle 2 inaccordance with the invention, in which all operations of the vehicle 2are performed fully remote, that is, without any need for a humanoperator to directly interact with a control system onboard the vehicle2 during the service procedure.

In the sixth embodiment, the service vehicle 2 comprises two caterpillartracks/rollers 6,7 coupled to two opposite vertical sides of a vehiclebody 3. At least one of the two other vertical sides of the verticalbody 3 is configured to receive at least one container handling vehicle200,300 to be serviced.

FIGS. 16-18 shows a particular configuration where service vehicle 2comprises two guiding pins 35 attached to each of the opposite verticalsides of the vehicle body 3 onto which the caterpillar tracks 6,7 areconnected. The ends of each guiding pins 35 nearest the containerhandling vehicle receiving side of the vehicle body 3 displays a wedgeshape allowing the contain handling vehicle 200,300 to be guidedcorrectly into the vehicle body 3. A remotely operated registration unit9 in form of a forward camera 9 a and a rearward camera 9 b is mountedon the top horizontal side of the vehicle body 3.

The transfer device 8 comprises a lifting mechanism 8 c which includesone or more vertical linear actuators 8 f. Each of the actuators 8 f hasone end connected to a pivot support 8 h pivotally couples to thevehicle body 3 with a rotational axis parallel to the underlying railsystem 108 and the other end to a lifting claw 8 d. The lifting claws 8d may be displaceable in a horizontal direction relative to the vehiclebody 3 by use of horizontal linear actuators 8 i, i.e. with a horizontalnon-zero component.

The service vehicle 2 is remotely operated by a remote control systemvia one or more onboard transmitters 36. Exemplary locations of suchtransmitters 36 may be on one, some or all of the vertical linearactuations as depicted in FIGS. 16-18. Alternatively, or in addition,similar transmitters 36 may be arranged on the vehicle body 3, withinthe registration unit 9, on one or both of the rollers 6,7, etc.

As for the above disclosed embodiments the caterpillar tracks/rollers6,7 have a length L extending across a plurality of grid cells 122,preferably four or more.

In the sixth embodiment the opening of the vertical containing handlingvehicle receiving side of the vehicle body 3, including any guiding pins35, has a minimum width G being equal to, or larger than, the overallwidth of the container handling vehicle(s) 200,300 to be serviced.

The procedure for picking up a container handling device 200,300 by theservice vehicle 2 according to the third embodiment may proceed in thefollowing way:

-   -   (FIG. 17 A) The service vehicle 2 approaches a position adjacent        to the one or more container handling vehicles 200,300 to be        transported using signal communication between a remote control        system and the one or more of the onboard        transmitters/receivers. If needed, the orientation of the        service vehicle 2 is changed so that the vehicle receiving        opening of the service vehicle 2 are facing towards the        container handling vehicle(s) 200,300.    -   (FIGS. 17 B and C) The service vehicle 2 is remotely guided so        that the container handling vehicle(s) 200,300 enters through        the receiving opening of the vehicle body 3, between the two        caterpillar tracks/rollers 6 so that the transfer device 8 is in        an interacting position, i.e. with the plurality of lifting        claws 8 d arranged on two opposite vertical sides of the or each        container handling vehicle 200,300. Alternatively, the service        vehicle 2 may be kept still, and the container handling        vehicle(s) 200,300 may be remotely guided into the vehicle        receiving opening. The correct horizontal position of the        container handling vehicle 200,300 inside the vehicle body 3 can        be further controlled by a stopper 37 arranged on the vertical        side opposite of the receiving opening. Such a stopper 37 will        also contribute to increase the stability of the container        handling vehicle 200,300 within the vehicle body 3. In the        example shown in FIGS. 16-18 this stopper is illustrated as a        horizontal extending bar arranged to abut the container handling        vehicle 200,300 when the latter is fully inside the vehicle body        3 of the service vehicle 2.    -   (FIG. 18 A) When the transfer device 8 is in the interacting        position relative to the container handling vehicle(s) 200,300,        the lifting claws 8 d are displaced horizontally using the        horizontal linear actuators 8 i until the lifting claws 8 d make        physical contact with the container handling vehicle(s) 200,300.    -   (FIG. 18 B) The vertical linear actuator(s) 8 f is/are remotely        operated, causing the vehicle body 3 to be lifted from the rail        system 108 due to the pivoting movement of the pivot support(s)        8 h. Due to the established physical contact between the lifting        claws 8 d and the container handling vehicle(s) 200,300, the        latter is lifted from the rail system 108, thereby setting the        service vehicle 2 in a transport position.    -   The service vehicle 2 is moved to its predetermined position on        the rail system 108, or out of the rail system 108, with the one        or more container handling vehicles 200,300.

The unloading process, i.e. the transport of the one or more containerhandling vehicles 200,300 by the service vehicle 2 to a predeterminedposition onto the rail system 108 for regular operation, proceeds equalor similar to the above described loading process, but in reversesequence.

In all embodiments, the rollers 6,7 comprise looped chains 6 d driven bytoothed belt wheels 6 a,6 b arranged within the chains 6 d. However, itmay be envisaged configuration where one or more of the toothed wheels 6a,6 b are arranged outside the looped chain 6 d. Instead of toothedwheels 6,7, the rollers 6,7 may comprise alternative drive mechanismsuch as wheels having other types of means for meshing or coupling totheir respective chains 6 d. Further, the rollers 6,7 may be composed ofcomponents other than endless belts, for example a set of wheels wideenough to cover at least one grid cell 122.

Even if only the sixth embodiment is disclosed without a dedicated spacefor a human operator, all the embodiments of the service vehicle 2 maybe easily configured to be maneuvered on the rail system 2 without theneed for an onboard operator 50, for example by operations performedentirely by a remotely located human operator 50 or by a fully or partlyautomated control system or a combination thereof.

It may also be envisaged embodiments where the full operation of theservice vehicle 2 is partly due to the operation of an onboard operatorand partly due to a remotely located human operator or alternatively acombination between the operation of an onboard operator and a fully orpartly automated control system.

In the preceding description, various aspects of the vehicle and thestorage system according to the invention have been described withreference to the illustrative embodiment. For purposes of explanation,specific numbers, systems and configurations were set forth in order toprovide a thorough understanding of the vehicle and its workings.However, this description is not intended to be construed in a limitingsense. Various modifications and variations of the illustrativeembodiments, as well as other embodiments of the vehicle, which areapparent to persons skilled in the art to which the disclosed subjectmatter pertains, are deemed to lie within the scope of the presentinvention.

REFERENCE NUMERALS

-   1 Storage and retrieval system/storage structure-   2 Service vehicle-   3 Vehicle body-   4 Container vehicle handling part-   5 Operational part-   6 First propulsion means/propulsion mechanism/rolling    means/roller/caterpillar track-   6 a First toothed belt wheel for each endless belt 6,7-   6 b Second toothed belt wheel for each endless belt 6,7-   6 c Inner surface of the endless belt 6,7-   6 d Looped chain/endless belt-   7 Second propulsion means/propulsion mechanism/rolling    means/roller/caterpillar track-   8 Transfer device-   8 a Base plate/Transfer device support-   8 b Transfer beams-   8 c Transfer motor/lifting mechanism-   8 d Attachment device/lifting hook/lifting claw-   8 e Transfer drum-   8 f Vertical linear actuator-   8 g Frame connected to vertical linear actuator and lifting hook-   8 h Pivot support for vertical linear actuator-   8 i Horizontal linear actuator-   9 Registration unit/image capturing unit-   9 a Forward camera-   9 b Rearward camera-   12 Operating system/control system-   12 a Emergency stop-   14 Handle-   13 Operator chair-   33 Security fence-   34 Inspection door-   35 Guiding pin-   35 a Wedge-shape at end of guiding pin-   36 Transmitter/receiver-   37 Stopper-   50 Operator-   100 Framework structure-   102 Upright members of framework structure-   103 Horizontal members of framework structure-   104 Storage grid/three dimensional grid-   105 Storage column-   106 Storage container-   107 Stack-   108 Rail system-   110 First set of parallel rails in first direction (X)-   111 Second set of parallel rails in second direction (Y)-   115 Grid opening-   119 Drop-off port column-   120 Pick-up port column-   122 Grid cell-   200 First container handling vehicle-   201 Wheel arrangement-   300 Second container handling vehicle-   301 Wheel arrangement-   302 Receptacle (for lifting hook 8 d)-   X First direction-   Y Second direction-   P Horizontal plane-   L Length of propulsion means 6,7-   W Width of propulsion means 6,7-   G Width a spacing between the first and second endless belt 6,7

1-18. (canceled)
 19. An automated storage and retrieval systemcomprising: a storage grid comprising storage columns arranged in rows,in which storage columns storage containers are stacked one on top ofanother to form stacks, a rail system comprising a first set of parallelrails arranged in a horizontal plane and extending in a first direction,and a second set of parallel rails arranged in the horizontal plane andextending in a second direction which is orthogonal to the firstdirection, which first and second sets of rails form a grid pattern inthe horizontal plane comprising a plurality of adjacent grid cells; atleast one container handling vehicle being configured to move on therail system, wherein the at least one container handling vehiclecomprises a wheel arrangement being configured to guide the at least onestorage container vehicle along the rail system in at least one of thefirst direction and the second direction; and a service vehicle formovement on the rail system, comprising: a container vehicle handlingpart for mechanical interacting with the at least one container handlingvehicle operating on the rail system, an operational part forcontrolling operations of the service vehicle, and propulsion means,wherein the propulsion means allow movement of the service vehicle inany direction over the top of the rail system during operation, whereinthe propulsion means comprises: a first caterpillar track comprising alongitudinal extending endless belt, a second caterpillar trackcomprising a longitudinally extending endless belt directed parallel tothe endless belt of the first caterpillar track, a belt motor drivingthe endless belts, wherein the first and second caterpillar track have,when moving over the top of the rail system an overall length Lexceeding the distance across two grid cells in the first direction andthe second direction, wherein movement of the caterpillar tracks overthe top of the rail system signify that the caterpillar tracks aresupported on the rail system, but do not engage with the railsthemselves.
 20. The automated storage and retrieval system in accordancewith claim 19, wherein the first caterpillar track further comprises atleast one belt wheel contacting the endless belt, wherein the belt motoris configured to drive the endless belt via the at least one belt wheel,and the second caterpillar track further comprises at least one beltwheel contacting the endless belt, wherein the belt motor is configuredto drive the endless belt via the at least one belt wheel.
 21. Theautomated storage and retrieval system in accordance with claim 19,wherein the first caterpillar track further comprises at least one beltwheel contacting an inner surface of first endless belt, wherein the atleast one belt wheel has a rotational axis parallel to a rotational axisof the endless belt, and the second caterpillar track further comprisesat least one belt wheel contacting an inner surface of first endlessbelt, wherein the at least one belt wheel has a rotational axis parallelto a rotational axis of the endless belt.
 22. The automated storage andretrieval system in accordance with claim 21, wherein the firstcaterpillar track and the second caterpillar track are spaced apart by agap in a direction of the rotational axis of the endless belts.
 23. Theautomated storage and retrieval system in accordance with claim 19,wherein the container vehicle handling part of the service vehiclecomprises a transfer device configured to transfer at least onecontainer handling vehicle between an operating position on the railsystem and a transport position within a vehicle body and a transfermotor configured to power the transfer device to allow said transfer ofthe container handling vehicle.
 24. The automated storage and retrievalsystem in accordance with claim 23, wherein at least part of thetransfer device is configured to move between an upper position and alower position relative to the horizontal plane.
 25. The automatedstorage and retrieval system in accordance with claim 23, wherein thetransfer device is arranged at least partly between the first and secondcaterpillar tracks.
 26. The automated storage and retrieval system inaccordance with claim 23, wherein the transfer device is configured tosupport the container handling vehicle from below.
 27. The automatedstorage and retrieval system in accordance with claim 23, wherein thetransfer device comprises a base plate onto which the container handlingvehicle may be supported.
 28. The automated storage and retrieval systemin accordance with claim 19, wherein the operational part of the servicevehicle comprises a propulsion means motor allowing movement of theservice vehicle along the horizontal plane and an operating systemallowing an operator to control and regulate both the direction and thespeed of the service vehicle relative to the underlying rail system. 29.The automated storage and retrieval system in accordance with claim 19,wherein the service vehicle further comprises a registration unit beingconfigured to allow visual inspection of the surroundings of the servicevehicle.
 30. The automated storage and retrieval system in accordancewith claim 19, wherein the service vehicle is arranged for transportingat least one of the at least one container handling vehicle in thehorizontal plane and for transporting one or more people.
 31. Theautomated storage and retrieval system in accordance claim 19, whereinthe service vehicle comprises a transmitter for establishing signalcommunication with a remote control system.
 32. The automated storageand retrieval system in accordance with claim 19, wherein the containervehicle handling part of the service vehicle comprises a transfer deviceconfigured to transfer at least one container handling vehicle betweenan operating position on the rail system and a transport position withina vehicle body, wherein the transfer device comprises an attachmentdevice for releasable attachment to the at least one container handlingvehicle, a vertical linear actuator attached at one end at leastindirectly to the vehicle body and the other end at least indirectly tothe attachment device, wherein the vertical linear actuator isconfigured to displace the attachment device relative to the vehiclebody in a vertical direction.
 33. A method for operating a servicevehicle in the automated storage and retrieval system according to claim19, wherein the method comprises the following steps: guiding theservice vehicle to a first position on the rail system adjacent to atleast one storage container vehicle by operating the operational part,controlling a transfer device to transfer the at least one containerhandling vehicle between an operating position on the rail system and atransport position above the rail system and guiding the service vehicleto a predetermined second position on or outside the rail system.